A new manufacturing unit has just been constructed and put into operation by your company. The basis of the manufacturing process is a special computer for control as developed by your research department. The plant has now been in operation for less than one week and is performing according to expectations. You wish to generate an activity network of your plant. 

A new computer has just become available on the market. This new computer can easily be installed at once in place of your present computer and will do the identical job at far less annual cash expense because of reduced maintenance and personnel costs. However, if the new computer is installed, your present computer is essentially worthless because you have no other use for it. Using this new computer you want to calculate float time of each activity. But accidentally the computer gives the negative float time. 

Is it possible for an activity the negative float time? 

Justify with reason. Also discuss with a suitable graph how break-even point determines the health of the company in terms of profitability?